Method for regulating fruit set



United States Patent 3,139,333 METHOD FOR REGULATlN G FRUIT SET Robert 1. Scott, Gasport, N.Y., assignor to FMC Corporation, New York, N.Y., a corporation of Delaware No Drawing. Filed Mar. 5, 1962, Ser. No. 177,228 3 Claims. (Cl. 712.6)

This invention relates to methods for chemically treating deciduous fruit trees to thin the fruit without damage to the foliage, fruit or vigor of the trees.

The thinning of fruits is.essential if good crops of desirable fruit are to be produced. In normal seasons, fruit trees produce considerably more fruit than the tree can mature safely. If left untreated, part of thefruit drops off due to natural causes, but too much fruit still remains resulting in the production of quantities of small fruit which are undesirable for marketing. Hence, the practice in all orchards is to thin the fruit in the early stages after setting. This requires a considerable amount of hand labor all of which must be done in a relatively short span of time. There has thus been a demand for some effective chemical treatment which would replace this hand labor.

Because of the possibility of poor pollination and the hazard of late spring frosts, most growers prefer to thin their trees after the fruit has set and a crop is assured rather than thinning in the blossom stage. The problem is to find a treatment that will effectively thin the fruit without malforming the fruit, leaving any toxic residues .and without damaging the foliage or adversely affecting the vigor of the trees.

I have discovered that effective thinning of deciduous fruits such as applies and peaches can be obtained without damage to the fruit, the foliage or vigor of the trees and without the deposition of toxic residues, by spraying the tree in the period between the development of the blossoms and substantial development of the fruit, with Example 1 METHACRYLYL CHLORIDE ROUTE 2 aniline in 8500 ml. of toluene was heated gently with stirring until all the aniline was dissolved. To the solution was slowly added over a period of 30 minutes, 755 g. (5.5 moles) of phosphorus trichloride, the temperature being allowed to rise to 85 C. The mixture was heated under reflux for 1.5 hours during which time solids separated which rendered stirring diflicult. The mixture was allowed to cool slightly and to the solution was added slowly 1041 g. (12.1 moles) of glacial methacrylic acid. When addition of the acid was complete, the mixture was heated under reflux for an additional 2 hours. At the end of this time the orange slurry was filtered through a heated Buchner funnel. The filter cake of amine hydrochloride was returned to the reactor and triturated with 4000 ml. of boiling toluene and again filtered through a' hot Buchner. The toluene filtrates were allowed to cool and the white solid which crystallized was isolated by filtration to give 1715 g. of product melting at 122-124 C and a surfactant. Typical formulations include the following: V

Example 3 2 lbs./ gal. Dicryl 23.40 Dimethylformamide 7.50 Isophorone 54.10 Emcol H300X 1.50

.an aqueous emulsion containing concentrations of the' To a stirred solution of 17.8 g. (0.11 mole) of 3,4-

dichloroaniline and 10.1 g. (0.1 mole) of triethylamine in 200 ml. of benzene was added dropwise 10.5 g. (0.01 mole) of freshly distilled methacrylyl chloride. The mixture was heated under reflux for one hour with stirring, then allowed to cool to room temperature. To the cooled mixture was added 100 ml. of 1% hydrochloric acid and stirring was continued for 0.5 hour. The benzene layer was separated and the aqueous phase was extracted twice with 50 ml. portions of ether. The combined benzene and ether solutions were washed with 100 ml. of water, separated and dried over anhydrous potassium carbonate. The solvent was removed by distillation to give 18.5 g. (76%) of solid product which melted at 123-125 C. Recrystallization from ligroinethanol gave a solid which melted at 124-126 C. Analysis.-Calcd..

C H CI NO: C, 52.20; H, 3.94. Found: C, 52.02; H, 3.67.

Example 2 METHACRYLIC ACIDPC13 ROUTE A suspension of 4460 g. (27.5 moles) of 3,4-dichloro- Emcol HSOOX (blends of polyoxyethylene glycol ethers combined with calcium salt of oil-soluble sulfonate) 13.50

Example 4 Dicryl 19.50 Dimethylformamide 6.18 Isophorone 43.53 Xylene 18.41 Emcol H300X -1 1,24 Emcol HSOOX 11.14

'- In using these emulsifiable concentrates, they are diluted in the orchard to the desired concentration of toxicant and applied as desired. These concentrates form good emulsions when mixed with water in any proportion.

The material may also be formulated as a wettable powder by combining the toxicant with any conventional powdery adjuvant and a dispersing agent. These wettable powders can also be made up into emulsions of the desired concentrations with water and can be used like the emulsifiable concentrates. Since they are somewhat more difficult to make into good emulsions, it is somewhat easier to work with the emulsifiable concentrate.

The following examples illustrate the use of the compound in the thinning of fruits. They are not of course limiting but merely illustrative of the invention.

Example 5 The emulsifiable concentrate of Example 3 Was used and dilutedto 300-500 ppm. with Water. The materials were applied to limbs of separate trees and comparedfwith an untreated check. The apples were of the Wealthy variety. The test was made in the blossom stage. The

. Q setting of the fruit was reduced as indicated in the following table:

TABLE v TABLE I Appln. Blossom Fruit Percent Plot Material Rate, Count Set Fruit p.p.rn. Set Rate Total No. Percent Material Applied, Clusters Fruit Fruit p.p.m. Set Set Dicryl1.6 300 ass 55 14. 2 11 .d 200 545 125 22.8 12 ..do. 100 468 197 42.1 Dicryl 300 119 47 40 19. Check (untreated). 138 43 30. 9 Check. 127 81 64 Dicryl..- 500 113 47 42 Cheek.. 133 v 92 69 10 Example 8 V In order to check the value of the method at the more Slight w1lt1ng and yellowmg of the fohage was noted, desirable application time when the f it is set, the but mere was no bad effect on the p when the material was applied to an orchard of Hale Haven pp matured, there was no Tesldne- V 15 peaches when the fruit had been set and was in the shuck- Example 6 split stage, but when about of the fruit surface was exposed. The emulsifiable concentrate of Example 3 TEST 0N APPLES was used, application was as in Example 6. The trees In this test the emulsifiable concentrate of Example 4 were wet to run-off. Three random replicates of each was used, diluted as indicated in the table. The emulsion treatment were made. The material was applied at rates was applied to Wealthy apple trees approximately ten days ranging from 200 to 500 ppm. Pre-application fruit past full blossom. A Bean 300 gallon orchard sprayer counts were made ten days before the test; post-applicawas used. The trees were wet to run-off. Checks of tion counts were made five Weeks after the test. The foliage conditions were made 8, 1 4 and ZI-days after orchard was wet by showers for about five hours shortly spraying. Flower cluster counts were made a few days after the application with temperatures in the low s. before spraying and 'fruit set was determined one month It should be noted that the counts were not made on the after spraying. The results are shown in the following complete trees but only on selected limbs which seem tables: to be of normal health and vigor which were tagged TABLE II Appll- Foliage Qondition cation Plot Material Rate, o p.p.m. After 8 days After 2 wks. After 3 wks.

15 Dicryl1.6EC..... 800 N,13,veryslightinjurytot0liage.- N,B,veryslightfoliageinjury..-.. Ni B, fCir/fiery slight injury to ma- 'ure 0 rage.

600 N,B,veryslightioliageiniury -.do N, Byvery slight foliage injury. 400 N, Y, very slight seatteredchlorosis N, C, B, possible slight leaf curl N, C, B, very slight foliage injury. 200 N,Y,veryslightchlorosispossible. N, Q, possible slight leai curl N, C, B, possible scattered very slight foliage injury. 20 Check (untreated) N, 0, possible sight leai curl N N.

N =no'rmal foliage. Y=chlorosis. 'B =n1arginal leaf burn. O =l af curl.

TABLE III when the counts were first made, About 1,500 to 2,000 fruit were counted initially in each test. The results P1 M t 1 tAppRlic1a= gllower Fsruit "Fruitlglgt 50 were as 5:

ot a eria ion a e, usters et per ppm. 7 Clusters TABLE VI 800 219 52 23.7 4trees 4trees 600 265 21 7.9 Appln. Pre- Total Percent 400 248 49 19.8 55 Plot Material Rate, Appln. Fruit Fruit 18 .do 200 352 137 38.9 p.p.rn. Fruit Set to Set 20 Cheek (untreated). 379 483 127.4 Count Mature 1 Dicr l 1 6 EC 500 1, 644 9a 5.8 7 5 a 1,382 i2 7 o. 2, 5s 2 Exactly the same group of tests as in Example 6, with 4 200 17644 164 mg the exception of rate of application, were run on Halo 5. Cheek (untreated). 1,508 359 23.8 Haven peach trees. The following results were obtained:

TABLE IV u g It will be noted that the fruit set was reduced about Appm Foliage Condition 50% by the appl1cat1on of either 200 or 300 ppm. of Plot Material Rate, the regulating agent whlle further reductions were ob-' 3 days 3 Wm tained at higher concentrations. The trees on which the fruit set had been reduced by 50% earned fruit of ex- Dicr'ylm 300 N N N cellent size and quality. Full equivalent trees in the -.--.do 200 N N, p0ssib1e N same plot were hand thinned by experienced operators. i t fjfif gj 'The plots were observed at weekly intervals for phyto- 1 d 100 N m N toxic symptoms and no more than very slight effects 31:1: gza gg ay N 11111:: N were observed. The fruit was tested after picking for evidences of Dicryl and none was found. N=norma1 f0nage Y=ch1omsis The trees which were more heavily thinned had, at

or. n

harvest, exceptionally large fruit. What was particularly noticeable about this fruit is that it was free of growth cracks which often occur when trees are hand thinned to as great an extent as was done with the Dicryl.

It will be observed from these tests that the growth regulant may be used over a wide range of concentrations, both to thin out the blossom clusters, and to thin the fruit after it has been set. Obviously the examples are illustrative of what can be done with the invention which is expressed in the following claims.

What is claimed is:

1. The method of thinning deciduous fruit which com prises spraying the trees at the stage from the time when the blossoms are formed to an early period after the setting of the fruit with an aqueous emulsion containing an effective amount and concentration to thin said deciduous fruit of N-(3,4-dich1orophenyl)methacrylamide.

2. The method of claim 1 in which the chemical is applied in an aqueous emulsion containing from 100 to 600 ppm. of methacrylamide.

3. The method of claim 1 in which the emulsion is applied to peaches at the shuck-split stage.

References Cited in the file of this patent UNITED STATES PATENTS OTHER REFERENCES Fertig: Proceedings of the Northeastern Weed Control Conference vol. 15, Jan. 4, 5, 6, 1961, pages 23-28 (page 25 of special interest). 

1. THE METHOD OF THINNING DECIDUOUS FRUIT WHICH COMPRISES SPRAYING THE TREES AT THE STAGE FROM THE TIME WHEN THE BLOSSOMS ARE FORMED TO AN EARLY PERIOD AFTER THE SETTING OF THE FRUIT WITH AN AQUEOUS EMULSION CONTAINING AN EFFECTIVE AMOUNT AND CONCENTRATION TO THIN SAID DECIDUOUS FRUIT OF N-(3,4-DICHLOROPHENYL)METHACRYLAMIDE. 